The present invention relates to a process for producing a vibrator for a piezoelectric motor.
Conventionally, processing of an elastic body of a vibrator for a piezoelectric motor is conducted according to steps shown by a flow chart of FIG. 5. For example, roughing of a metallic material into a freely chosen shape of an elastic body is conducted (Step 501), and next, finishing by cutting the material into a predetermined shape is conducted (Step 502). The step of roughing is described in the following according to a process of producing an elastic body shown in FIG. 6. For example, in order to obtain the elastic body shown in FIG. 6(c), roughing of a metallic material 61 shown in FIG. 6(a) is conducted to make the metallic material 61 have a predetermined thickness and the shape of a disc shown in FIG. 6(b). Next, finishing is conducted and an elastic body 69 having a comb-like projection part 69a is formed. The characteristics of transmission of vibration and expansion of vibration which show performance of the elastic body 69 depends on the shape of the comb-like projection part 69a formed at this finishing step.
On the other hand, processing of a piezoelectric element of a vibrator for a piezoelectric motor is conducted, for example, by conducting finishing of the outline and the thickness of a piezoelectric ceramics material into a predetermined shape by way of cutting and lapping the piezoelectric ceramics material, forming an electrode, conducting polarization processing for imparting piezoelectric activity to the piezoelectric ceramics material, and forming an electrode for driving.
A vibrator is obtained by fixedly attaching the elastic body to the piezoelectric element, which elastic body and piezoelectric element are obtained in the abovementioned processing (Step 503).
However, in the conventional process for producing a vibrator, the outline of a vibrator which has a close relationship with the working characteristics of a piezoelectric motor should be finished very carefully. Further, handling of a piezoelectric element and an elastic body when they are fixedly attached to each other is done one by one. These limitations result in high manufacturing cost and instability of yield in manufacturing of a piezoelectric motor. In addition, the cutting processing applied to an elastic body causes mechanical deformation or thermal deformation of a cutting edge and a machine, which makes it difficult to process a workpiece in minute detail with high accuracy.
The present invention is made to solve the abovementioned problems. The object of the present invention is to provide a process for producing a vibrator for a piezoelectric motor with which mass production with batch processing like production of semiconductors is materialized, the manufacturing time is shortened, and the manufacturing cost is lowered, and, with which processing in minute detail with high accuracy is easily conducted for attaining miniaturization and advanced performance of a piezoelectric motor.